Sinkholes pose threat to Dead Sea communities – YNET

Florida tragedy which saw doline swallow man’s house turns local authorities’ attention to situation in Israel, especially in southern communities. Residents say there are no disaster contingencies

Ilana Curiel
Published: 03.04.13

The recent tragedy in Florida, in which a large sinkhole opened up under the Tampa home of Jeff Bush, 36, and literally swallowed him up while he was in his bedroom, has sparked fear in the heart of the residents of the communities near the Dead Sea – an area prone to swallets of all sizes.

Found worldwide, sinkholes are a natural depression in the Earth’s surface caused by a geological dissolution of layers of soluble bedrock. The formation of sinkholes, also called “swallets” or “dolines,” can be gradual or sudden, and they vary in size from 3.3 to 2,000 feet.

To date, no one has been able to come up with a technology that would enable areas prone to the phenomenon to predict or prevent dolines from forming.

The communities most affected by sinkholes in Israel are those adjacent to the Dead Sea. The Tamar Regional Council alone is the site of 3,000 of them.

Geologist Eli Raz said that many of the new sinkholes in the area are the result of the decrease the Dead Sea’s water level.

Raz warned that as the phenomenon becomes more frequent – and given its unpredictable nature, something has to be done to assist the communities dealing with them.

“I hope he Florida tragedy increases awareness to the problem,” he said.

“This area is riddled with sinkholes,” Avi Rotem, who serves as the council’s city engineer, told Ynet. “This poses a setback to the area’s development, but it’s important to remember that these dolines are not the same as the ones you find in Florida.

“This is a very serious problem and we’re not really dealing with it – we just abandon areas with sinkholes.”

Dr. Michael Tsesarsky of the Department of Structural Engineering at the Ben Gurion University said that since the bedrock in Israel is different that Florida’s, “We’re in a slightly better situation, than they are.”

Still, Tsesarsky said that over the past 10 years, hundreds of new sinkholes have formed, some underwater.

He further warned of sinkholes tendency to merge into “mega-holes.” “Unlike in Florida, the Dead Sea area is relatively unpopulated and the hotel strip is doing fairly well,” he said.

“The big question is, of course, how to detect swallets in advance. Currently there are researches trying to apply satellite imagery to it, and the Israel Institute of Technology is developing technology based on fiber-optics.”